Question

How can I tell a rational and irrational number apart?

Answer 1

Well, an irrational number such as `pi` has an `oo` number of digits after the point and they do not present a recognizable pattern.
A rational number (the result of dividing two integer numbers) either stops after some digits or has `oo` digits but following a pattern (repetitions for example).
Examples:
Rationals:
`5=5/1`
`1/2=0.5`
`2/3=0.6666666666....` always the same number after the point!
`6/11=0.5454545454...` always the same pattern of repeating 54!

An irrational number doesn't follow a pattern after the point, the decimal goes on forever without repeating. Remember that you cannot write your irrational as a fraction of two integers.

You can have "important" irrational numbers as `pi` oe `e` or the result of square roots as `sqrt(2)=1.414213562....`.